Update README.md
custom payload support
update docs
fix documentation T -> HelloWorldConfiguration
* make getPayloadClass() public
* revert field visibility
add @Notnull on serviceInstanceFactory
Add default implementation of bundle
update documentation
fix class signature documentation
Support easier upgrade

* Rename DiscoveryBundle -> AbstractDiscoveryBundle
* Rename BasicDiscoveryBundle -> DiscoveryBundle
Merge pull request #6 from theo/master

#5 custom payload support
Upgrade dependencies:

- maven-surefire-plugin from 2.17 to 2.18
- maven-source-plugin from 2.2.1 to 2.4
- jacoco-maven-plugin from 0.7.1 to 0.7.2
- coveralls-maven-plugin from 2.2.0 to 3.0.1
Ran code through the formatter